The prior LED straight tube type lamp mainly comprises a tube body, a lamp cover arranged on two ends of the tube body and a lamp strip which is arranged in the tube body, wherein the lamp cover and the tube body are adhered generally by adopting chemical adhesives. The adhesives fix the lamp cover on the tube body so that the structure is simple, but the solidification or drying of the adhesives needs certain time, and therefore the product assembly needs longer time. Meanwhile, the adhesives left at gaps between the lamp cover and the tube body are organic chemicals which slowly decompose or dissociate some chemical substances to erode the surface of the tube body of plastic material so as to result in the aging phenomena such as stains, streaks, cracks and the like, so the service life is substantially shortened; furthermore, the chemical adhesives can generate nasty smell, and can harm the operators and generate pollution to the environment during use.
In addition, the lamp strip generally comprises a heat diffuser and a circuit board, wherein the heat diffusion effect of the circuit board is the key technique of making a light emitting dioxide illuminator, and therefore, the techniques of compounding the heat radiator/body with the circuit board/layer through an insulating plate/layer have existed. The most common technique is to make an aluminum-base copper-clad foil laminate into a printed circuit board and then assembling with the heat diffuser through heat conducting silicone grease by using screws.
Undoubtedly, the heat diffusion effect is poor. For example, although all Chinese patents of publication numbers (1) CN201191609Y, (2) CN201110471Y and (3) CN2926814Y have better heat diffusion effect, the main defects of these patents are obvious:
1. poor heat diffusion effect, as the foresaid patents of the publication numbers (1), (2), (3) are provided with uniform insulating layers/plates in between circuit layers/plates and heat diffusion layers/plates, the insulating layers/plates have large heat resistance and low heat transmission efficiency so as to result in poor heat diffusion effect; especially the patent of the publication number (2) adopts the mode of insulating plate assembly, and the heat diffusion effect is worse as gaps exist between relevant components; similarly, the patent of the publication number (3) is further provided with an insulation layer between the circuit board and the heat diffusion body, the heat diffusion body is integrated on a casing, so that the heat diffusion effect is worse.
2. unreasonable structure, all the foresaid three patents are in assembly structure which certainly has influence on the heat diffusion effect; the heat diffusion layer of the foresaid patent of the publication number (1) is a copper-aluminum double-metal composite layer, it is impossible to make absolute seamless connection after all despite of being made by adopting cold rolling pressing technology; as numerous micro-fine depressions exist on the surfaces of the copper plate and the aluminum plate, and the copper plate and the aluminum plate have straightness difference, a large amount of air must be contained between the connection surfaces of the copper plate and the aluminum plate and gas phase heat resistance exists between both, which directly has a strong impact on the heat diffusion effect of the heat diffusion layer.
3. Poor reliability, the insulating layers/plates of the foresaid three patents indefinitely are provided with insulating layers with the flame resistance and the surfaces of the circuit boards are not provided with insulating welding resisting layers, so that it is possible to generate short circuit and trigger fire alarm. And
4. complicated assembly and connection of the circuit layers/board and the LED light emitting dioxide, the foresaid patent of the publication number (1) realizes the electric connection of both through a base plate; and the patent of the publication number (2) realizes the electric connection of both by making the LED light emitting dioxide penetrate out of a through hole of the insulating plate.